Anemia

Definition

Anemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues.

Other types of anemia include:

Anemia due to B12 deficiency

Anemia due to folate deficiency

Anemia due to iron deficiency

Anemia of chronic disease

Hemolytic anemia

Idiopathic aplastic anemia

Megaloblastic anemia

Pernicious anemia

Sickle cell anemia

Thalassemia

Causes

Although many parts of the body help make red blood cells, most of the work is done in the bone marrow. Bone marrow is the soft tissue in the center of bones that helps form all blood cells.

Most often, healthy red blood cells last between 90 and 120 days. Parts of your body then remove old blood cells. A hormone called erythropoietin (epo) made in your kidneys signals your bone marrow to make more red blood cells.

Hemoglobin is the oxygen-carrying protein inside red blood cells. It gives red blood cells their red color. People with anemia do not have enough hemoglobin.

The body needs certain vitamins, minerals, and nutrients to make enough red blood cells. Iron, vitamin B12, and folic acid are three of the most important ones. The body may not have enough of these nutrients because:

Changes in the lining of the stomach or intestines affect how well nutrients are absorbed (for example, celiac disease)